The present invention relates to a DC voltage transformer with an inductance fed by a primary voltage and an oscillator stage switching the inductance for the generation of a secondary voltage.
Voltage transformers of the initially stated type can be used for a variety of tasks. For passenger protection devices in vehicles, DC voltage transformers are required in the event that the operating voltage (onboard supply system voltage) falls below a permissible limit value so that the operation of the passenger protection device is questionable. For the primer of an airbag to function properly, a given minimum voltage must be available so that firing delays or failures are avoided. If, for reasons not further discussed here, a reduction of the operating voltage of the motor vehicle occurs, the initially cited DC voltage transformer can be used to generate from the lower operation voltage a higher supply voltage for application to the primer in the event of the need to release the passenger protection device.
Further discussion regarding these problems can be found in German Patent No. 35 06 487.
In U.S. Pat. No. 4,013,935 a DC voltage transformer of the initially stated type is disclosed which is provided with a voltage comparator stage. The known DC voltage transformer is equipped with an oscillator stage provided with a switching transistor, wherein the collector-emitter voltage of the switching transistor is compared with a predeterminable reference signal by means of the voltage comparator stage.